1. Field of the Invention
The present invention relates to a multi-axis motor controller used to control the driving of multiple servo motors for enabling multi-axis control in an industrial robot or the like.
2. Background Art
The conventional multi-axis motor controller is equipped with a separate dedicated control unit for the servo motor associated with each axis. Each control unit is provided with numerous connectors for establishing the required electrical interconnections. Numerous cables are also required. The conventional system is therefore expensive owing to the high cost of the large number of required components and the considerable expense of installing the complex wiring.
To cope with this problem, Japanese Public Disclosure No. Hei 8-256500, for example, teaches a configuration in which a group of functional element units are laid out on and fixed to a circuit board provided beforehand with circuit wiring. The attachment of the laid-out functional element units to the circuit board enables functional element unit side connectors to engage with circuit board side connectors through the circuit wiring to establish electrical connection among the functional element units. This architecture reduces the number of connectors by simplifying the wiring layout and improving the connector arrangement. Moreover, the interconnection of the functional element units through the connectors results in a more rational wiring layout that enables a reduction in the number of wires. This also simplifies the wiring. In addition, the architecture enhances the reliability of control operations by eliminating wiring mistakes and helps to prevent external noise from getting into the wiring.
This conventional technology achieves its advantages by grouping the units, engaging the units with the circuit board through connectors, and utilizing wiring provided on the circuit board beforehand to establish the required electrical interconnections. At the same time, however, the architecture offers no flexibility in laying out the units in the control panel. This makes it impossible to optimize control panel space utilization.
In addition, the fact that the cables interconnecting the units are of different special types complicates the wiring and also reduces the number of identical connectors, cables and other components. This increases the number of component types and raises the unit cost of the components.
The invention will be better understood and other objects and advantages thereof will be more apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings.